Field of Invention
The present invention relates to an electromechanical device and, in particular, to a fan.
Related Art
In order to improve the rigidity of the bushing structure of a fan, it is usually to substitute the conventional integrally formed plastic bushing and plastic fan frame with a plastic fan frame in cooperate with a metal bushing made by brass turning process. Herein, the plastic fan frame and the brass metal bushing are bound by injection molding.
Although the design of metal bushing is benefit to improve the rigidity of the entire bushing structure and is capable to provide anti-vibration function in the high-speed fan, it still has some drawbacks. (1) The metal bushing is mostly made of brassiness, so the material cost is high. (2) The metal bushing is made by brass turning process, which has high manufacturing cost and long working term. Besides, the design of the bushing may also affect the number of steps in the brass turning process. In order to well control the cost, the metal bushing generally has simple design and thus no or few flexibility. (3) Moreover, since the brass material is easily deformed, the brass metal bushing may be deformed while being disposed in the fan frame plastic mold during the injection molding process. This deformation will cause undesired tolerance in the following assembling procedure of the bushing structure.
Therefore, it is an important subject to provide a bushing structure with lower cost and reinforced rigidity and a fan configured with the bushing structure.